Yeast Harvesting Guide

[johnnyboy1965]

At any rate, it does sound like freezing yeast is a great means of storing yeast long term.

Been doing it for 2-3 years without any glycerine etc!
Does need a starter though.

You really do need to add glycerine, because if you dont the frozen water will damage the yeast cell walls. You should also use a starter, if just to prove the viablity of the yeast.
On a side note ...why not make yourself a stir-plate. Its quite easy to do (even with my limited knowledge of electronics) and its fun...and beneficial

 

[beerguzzler8518]

I don't wash it I just put the slurry in a sterilized 2l PET bottle, put the lid on and keep in the fridge. 2l will seperate out into 1l of yeast and trub and 1 l of beer. The beer and CO2 keeps it sterile. If you use it with in a few months it should be fine or you could make a starter to get it going again.

The only reason I don't wash it is because I could never see differing layers and always had dificulty in splitting the layers I did see. Perhaps it is advisable to was but certainly keeping it in beer is a good idea.

I am also going to try freezing some with glycerine. :thumb:

Would I be right in thinking, that you simply pour the beer away and then pour the yeast/trub into the fermenting bin with the new wort?

 

[simon04]

Thanks for the info.

Just what I need, now that I've invested in phials of yeast, which cost circa £7 a time!

I'm also intrigued with the idea of freezing - especially if I'm not going to brew again soon (or brew with the same yeast again soon).

Does this work with Lager yeast too??

 

[dennisdk2000]

Thanks for the info.

Just what I need, now that I've invested in phials of yeast, which cost circa £7 a time!

I'm also intrigued with the idea of freezing - especially if I'm not going to brew again soon (or brew with the same yeast again soon).

Does this work with Lager yeast too??

Yes, in this respect, all yeast are created equal! :thumb:

Dennis

 

[shuggie159]

Alternative method for cornie users

I have had very poor success storing yeast under distilled pressure cooked water in the fridge. After about 3 weeks it goes grey and stinks (autolysis?).

So I now have developed a system.

Works like this....

After a brew I recover the wort by wringing out the old hops, sieve it and let it stand for an hour or two to clear, then pop it in small jars in the pressure cooker and autoclave it for future use as starter fuel. I think if you were brewing substantially different styles you may need several stored wort types.

At the end of a cornie I use the dregs, usually a good egg cupful of thick stuff, by tipping in some of the saved wort (above) swilling and transfering to 2 litre conicle on a stir plate. Within 2 days this usually will produce enough material to inoculate a 23lit brew in one itteration (I guess 1.5 - 2 Billion cells). If I think it looks a bit wishy washy I give it a second run through on new wort)

I have two rotating brews on the go, in cornies. [actually I rotate two differing yeasts, a 1968 and an SO4 cos I usually do an English Ale then an American Pale alternately)

So I have no storage issues. It is my observation that yeast keeps better under beer than in water etc in your fridge.

 

[Camberwell Canary]

Just finished bottling my first brew. All the gunk from the primary fermenter is in a sterilised flask in the fridge.

Thanks for producing this guide.

As a beginner I'm a little confused by some of the captions under the photos. Just to be clear:

1. I decant the liquid at the top into a new sterilised container (and chuck the solid stuff at the bottom - the trub)
2. Wait a bit longer for the liquid in the new container to settle out.
3. At this point, do I keep the liquid at the top or the stuff at the bottom?

Thanks

CC

 

[LeithR]

@ Camberwell Canary,
At the first stage when you have 3 levels - liquid, yeast, trub (at the bottom). I keep both the liquid and the yeast (middle layer). You can at this stage rinse the yeast to get rid of the original brew by adding boiled and cooled water to the container, give it a good swirl - don't shake it as it will go every where - once swirled let it settle then throw the liquid away and do it again. Once the mix has settled throw the liquid away and use the residue layer of yeast. You can keep in the fridge for a short period, to keep it in the Freezer for longer you can mix in 50% glycerin and mix it in with the yeast then freeze. This will last for a long time.

Whichever approach you take make sure you make a starter wit the yeast to ensure that it is viable, both approaches can be used together, it just depends on how long between brews. You can also split up the yeast so an initial split batch of yeast can be used in a number of other brews in parallel in the future.

There are other things to be aware of, last week for instance I started a cider using yeast recovered from 3 bottles of a previous batch of my own cider. In the original batch of cider I had used a Weston's Old Rosie yeast cultured from a single bottle of W.O.R. Again I made a starter and the new batch is going like a train!!

 

[Camberwell Canary]

Sorry to be a pedant. When you say "You can at this stage", do you mean after the first decant?

Steps are as I now see them:

1. Stick all gunk in flask in fridge (done this and it does look like there are three layers)
2. Pour off the beer and yeast layers. Bin the trub (I assume the yeast layer is reasonably liquid and decants easily off the trub)
3. Add sterile water and shake.
4. Pour off liquid.
5. Repeat steps 3 and 4 (optional).


Once I'm clear I'll take pictures and add to the thread.

 

[LeithR]

@Camberwell Canary,
Yes, thats what I mean.
Your point 2 - the liquidity of the yeast can vary, I think, but not absolutely sure it is type dependent, its an area I'm still exploring. So for instance a Nottingham yeast may be more liquid than an SO-4 yeast. Don't forget that some yeast floculate (clump up) more than others, this causes you to swirl some yeasts more vigorously than others.

 

[Camberwell Canary]

Didn't succeed :-(

Couldn't get the yeast to separate from the trub - it just kind of mixed in as soon as I started pouring. Perhaps it was the type of yeast (White Labs Burton Ale).

Will try harvesting from a bottle per Graham Wheeler's book. This sounds simpler.

 

[ibrewthereforeiam]

My experience with yeast.

Never froze yeast as I have never needed to. If I go awhile without using that harvested yeast, I just buy new. It's cheap and fresh.

I have cultured yeast from a single cell. I was however, in a lab under proper conditions and I haven't done it at home.

I currently acid wash yeast at home and here's how and why:

Once fermentation is done, I harvest my yeast by pouring it into a 1.8 liter container. (sorry i'm used to gallons so I tend to use decimals for liters)
I harvest day of brewing. You are able to let the yeast sit in that 1.8 L container for up to 2 weeks without stressing out the yeast too much.
Anything after 2 weeks, I dump the yeast and harvest from a more recent batch.
Yeast is everything to get a beer fermented so, when in doubt just buy a new vile of yeast as it is cheap. You put a lot of work into brewing up that batch of beer and it wouldn't be very fun to have it contaminated.
This next step is almost done by "feeling"....stick that yeast into the freezer just before you pitch it into your wort. Don't completely freeze it but try to get it as close to freezing as possible. What this does is, the healthy yeast cells close up as it is attempting to go into hibernation. Once you get it to that temp...add phosphoric acid until you reach 2.3 ph. You can do this out in the open because no bacteria survives at that ph level. What happens once you do this, is that strong ph kills off any mutated or weak yeast cells and leaves the healthy yeast to live. As long as you keep the yeast at that near freezing temp, you can have it stay at that ph for up to 2 hrs. I usually pitch the yeast at that ph after about 5 minutes. In about 5 hrs, I have a nearly full krausen and I have kept the same yeast for over a year with this method. Try it out, it's easier than you think. Now remember, you do have to cycle that yeast into fresh batches of beer every 2 weeks for this to be effective.

 

[evanvine]

Your 2 week limit is interesting.
I have previously washed yeast in phosphoric acid at pH 2 - 2.5, but subsequently rinsed again with demin water before freezing.
I don't brew that frequently, but do have a bank of yeast grown from various pints of "carry out".
These can take up to 36 hrs to form the krausen, but the taste is worth the wait!
I have frozen cultures over 2 years old that work!

 

[ibrewthereforeiam]

Your 2 week limit is interesting.
I have previously washed yeast in phosphoric acid at pH 2 - 2.5, but subsequently rinsed again with demin water before freezing.
I don't brew that frequently, but do have a bank of yeast grown from various pints of "carry out".
These can take up to 36 hrs to form the krausen, but the taste is worth the wait!
I have frozen cultures over 2 years old that work!

Wow man! 2 years! That's the absolute longest time I've ever heard of. No issues with lag, or any odd off flavors?

Well I use the phosphoric acid method because it has worked the best for me over the years. That is simply because I'm able to brew to frequent. I would love to divulge in other yeast harvesting methods. Freezing seems very popular with people on this website. Something
I've never done. Mind you my methods come from a brewery I worked at for several years that included a lab. I kinda took that home with me I guess...

 

[dennisdk2000]

Well I use the phosphoric acid method because it has worked the best for me over the years. That is simply because I'm able to brew to frequent. I would love to divulge in other yeast harvesting methods. Freezing seems very popular with people on this website. Something
I've never done. Mind you my methods come from a brewery I worked at for several years that included a lab. I kinda took that home with me I guess...

One of the great things about this forum is that it is made up of people from different back-grounds and who brew in all sorts of different ways. Different brewers have different requirements and therefore many diverse methods exist for doing the same thing.

I wish I had had the opportunity to work in a brewery, and I too would have taken some of that knowledge home with me! And it's great to hear about knowledge on here - I realise that there are some differences in commercial brewing and home brewing, but that doesn't mean that you can't translate some knowledge from one to the other.

Looks like I may have to look at acid washing know! :shock:

Dennis

 

[ibrewthereforeiam]

Looks like I may have to look at acid washing know! :shock:

Dennis[/quote]


Nice, if you have any questions about acid washing, just ask away. I have been doing it for years and I have kept yeast healthy for over a year with that method.

 

[rpt]

Where do you get phosphoric acid?